An electrical switching device, such as for instance a compact circuit breaker, has one or more moveable contact arm bridges, in order to open and close a current circuit. In the switched-on state, the contact arm bridge is to securely close the current circuit. In the event of a short circuit, the contact arm bridge is to open very quickly by electrodynamic forces independently of an actuation mechanism, for instance a latch and an over-current release, of the electrical switching device. This is ensured by way of various opening mechanisms. The moveably mounted contact arm bridge with the opening mechanism is mounted in a rotor housing. The rotor housing generally consists of a single element. Depending on the opening mechanism, it may be necessary for the rotor housing to consist of two or more elements.